I have a distributor on my car. It came that way. Normally it is very reliable except that the condenser can fail and the points can burn. So I put an electronic ignition module in the distributor. No more troubles, right? Wrong.

I had a mysterious miss when accelerating. The miss was random and only happened once every dozen revolutions or so. I switched back to the mechanical points and the miss is gone. Not that I will miss it. (Pun intended.)

The coil and condenser work in tandem to create the spark. It is really an induction-capacitor system. I am wondering if that is the reason the electronic ignition system did not work. Or maybe it was just a bad part. The gap is not adjustable and very small. I cannot think of any other reason why it caused my engine to run badly. Can you?

Neil

Perhaps it was rejection, similar to organ transplants in humans.

You may need a ballast resister inline to make sure the voltage remains stable

This type of ignition system works flawlessly...

A "high speed miss" in the situation you describe is very often associated with a worn dist bearing causing point bouncing. If the wear is slight it might not affect the points which in this case are a bit forgiving. The module with it's small gap would react differently to a slight wobbling shaft causing the gap to change.

Over 10 years ago, I added a ground wire to the Bosh 009 style distributor with an electronic ignition module and the "Mysterious Miss" stopped. It's very important that the distributor body has a good ground return when using an electronic ignition module.

A friend suggested that I did not have the right coil for an electronic ignition. I bought the Blue Coil made by Bosch from one of the air cooled VW parts houses. There are inferior copies out there so I had to make sure I got the genuine one. It is recommended for use with electronic ignition and puts out a hot spark. It has an internal ballast resistor. The primary windings with the resistor is 3 ohms.

I first tried it with the mechanical points and it worked fine, no missing. I then re-installed the electronic ignitions and it worked fine with that too. No missing. My ignitions switch is wired so that I can switch in or out the external ballast resistor, which is only 0.6 ohms. It made no difference whether this small ballast resistor was used or not.

I am going to keep the electronic ignition in the car and will report back if I have any problems with it.

When Chrysler switched from mechanical distributors to electronic, they continued to use the same coil. I cannot think of a reason that you would need a different coil if all that was changed was a mechanical breaker plate for an electronic unit that essentially does the same thing as the mechanical. Ballast resistors were typically used to drop the voltage from 12V to a bit above 7V to prolong the life of the points in a mechanical system. If you are running 12V you need to check with the manufacturer of the electronic system to see what voltage it requires. I'm betting that the electronic system needs 12V unless it was specifically manufactured for a 6V car. If that is the case, the ballast (voltage dropping) resistor will leave too little voltage at the distributor for satisfactory (or perhaps any) operation.

Try four coils and a timer!

John,

It is a 12 volt car.

I don't understand either why you would need a different coil other than perhaps the capacitor is missing. I do know that a coil and a capacitor work together, even in the stock Model T coils. I also know that when you look at the specifications for different coils, some are recommended for electronic ignition. I also know that the new coil works better than the one I took out.

The new coil has an internal ballast resistor so that, I guess, the windings and mechanical points, if used, are protected. The electronic ignition is wired up separately so that it gets 12 volts regardless of whether I run with an external ballast resistor or not.

The capacitor absorbs the current when the points open and then sends it back to the primary windings in the coil. This does two things. It keeps the points from burning and it causes the coil to produce multiple sparks. It is actually a tuned L C circuit. I think that with the electronic ignition there is only one spark as there is no capacitor. This may be why the higher output coils are recommended for electronic ignition. A points system will not operate with a burned out capacitor, one that is open. It will make a spark but weak and the engine will not run without missing.

Neil

Don't be such a dick Larry. It is a system already on a car. I find that while you do know quite a bit about T's, the majority of your replies are useless due to your total lack of open mindedness

Gary,

It is OK. I don't mind. Larry is entitled to his opinion and a lot of forum members have strong opinions about the stock ignition system.

Les,

I am going to add the ground wire when I get home from work tonight.

Funny thing - the distributor and electronic ignition are missing on my T as well, but it runs just fine. ?!?

They are both OK in my book. The distributor is so common on T's that I don't think it should be put down in any way. Now the usual "reason" a car ends up with one is that a former owner might have been talked into it being told it's more reliable and has less parts. Or perhaps it would cure some problem or other. Whatever. They are numerous as h*ll. I'm pretty sure I'd keep it if it as there.

Why not just start with a "Shove-or-Lay" and be done with it ? Got them kewl overhead valves and all, saves you the trouble of putting a "Rajio" or "Frontiac" on a dumb ol' model T, no stoopid planetary transmission neither, so you don't got to go hunting up a "Walford" gear box or nuthin' - it's all done up right for you with no fuss !

Rich,

I don't dislike hot rods but prefer antiques.

For a driver, I don't think the distributor detracts from the car. It is still a Model T with a Model T engine, just a different ignition system.

Neil